It's generally good when a car fuse blows because in most cases it prevents something more serious expensive from occurring. Compared to all other automobile parts, a fuse is dirt cheap. The failure of a fuse does, however, necessitate investigation into the cause so that the problem can be corrected.
The fuses installed in a car perform the same type of function as fuses installed in some homes and most electrical and electronic devices. When the current flowing through the fuse exceeds the fuse's current rating, the element in the fuse melts and breaks the circuit to discontinue current flow. When this happens, it means that whatever the accessory -- radio, wipers, horn -- the fuse is inline without allowing too much current to flow.
The cause of this excess current should be immediately identified and corrected. Faulty wiring or defective wiper motors can cause excessive current flow, resulting in a blown fuse. Defective switches may cause short circuits. Wipers frozen under ice can cause a blown fuse by impeding wiper movement. Other electrical components, such as heating and cooling blower motors, power seats, electric fuel pumps or air conditioner can all cause fuses to blow.
In many cases a blown motor circuit fuse may indicate a shorted motor. When troubleshooting leads to the confirmation of a blown fuse, the first thing to do is replace the fuse, making sure to exactly match amp rating. If this corrects the situation it may be the result of an intermittent power surge possibly caused by a bare wire, which should be located and repaired. If the failure is still present, do a thorough check of the wiring for loose connections in the failing circuit.
Pay attention also to the battery lead attached to the motor and ensure a secure connection. Replacing a blown car fuse is a fairly simple procedure. Most cars have small plastic-encased fuses that push straight in and pull straight out.
Use needle-nosed pliers or small tweezers-like grippers made for this task. Replace the blown fuse with one of identical amp rating. Plastic fuses are color-coded so the replacement should be the same color.
Glass fuse amp ratings are distinguished by differences in the length of the fuse.
They are removed by lifting one end at a time. Discard blown fuses and obtain a new spare. Some readers may have seen a "60 Minutes" program from a generation ago where a car was rigged with a simple malfunction and taken to several repair locations. Estimates for the repair varied over an incredible range for something that was just a few dollars to repair.
Instances like this still happen each day. So it would be most prudent to check and replace fuses yourself before taking your car in for repairs. Car fuses are very inexpensive. This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information.
To submit your questions or ideas, or to simply learn more about It Still Runs, contact us. What Makes Car Fuses Blow? What To Do When Car Fuses Blow When troubleshooting leads to the confirmation of a blown fuse, the first thing to do is replace the fuse, making sure to exactly match amp rating. About the Author This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information.
Photo Credits car fuses image by Witold Krasowski from Fotolia.The electrical system in every home features a system of circuits controlled and protected either by circuit breakers or fuses. Most of today's homes now use circuit breakers to offer this control and protection to individual circuits, but older homes that have not had their electrical systems upgraded may use fuses.
The circuit breakers or fuses are normally found in a central main service panel. Circuit breakers are lever-operated devices with ON-OFFs witches, while fuses are glass and ceramic cylinders with screw-in sockets. You likely already know where your main service panel is located and whether your system uses circuit breakers or fuses.
And you probably also know that when all the lights and fixtures in a portion of the house go dark or dead at the same time, it's because one of those circuit breakers has "tripped" or one of those fuses as blown. These devices are designed to automatically shut off power to the circuit when problems occur. In the case of circuit breakers, the immediate answer is to find the breaker that has tripped and reset the lever to the ON position.
When a fuse blows, a metal filament inside the fuse has burned through, meaning that you'll need to replace the fuse with a new one. But in most cases, the breaker or fuse is just doing its job when it pops.
An overloaded circuit is the most common reason for a circuit breaker tripping. It occurs when a circuit is attempting to draw a greater electrical load than it is intended to carry.
When too many appliances or light fixtures are operating at the same time, the internal sensing mechanism in the circuit breaker heats up, and the breaker "trips," usually by means of a spring-loaded component within the breaker. This breaks the continuous pathway of the breaker and renders the circuit inactive. The circuit remains dead until the breaker lever is reset to the ON position, which also re-arms the internal spring mechanism.
The circuit breaker or fuse is sized to match the load-carrying capacity of the wires in that circuit. Hence, the breaker or fuse is intended to trip or blow before the circuit wires can heat to a dangerous level. When a circuit breaker regularly trips or a fuse repeatedly blows, it is a sign that you are making excessive demands on the circuit and need to move some appliances and devices to other circuits.
Or, it may indicate that your house has too few circuits and is in need of a service upgrade. A short circuit is a more serious reason for a breaker tripping. A "hard short" is caused when the hot wire black touches a neutral wire white.Every vehicle has a fuse box somewhere in the cabin, usually underneath the steering column near your feet or hidden within the glove box.
These fuses are safety devices consisting of a strip of wire that melts and breaks an electric circuit if that current exceeds a safe level. You will know is you blow fuse because any of the components on that circuit will stop working, like the radio, the interior lights, or the electric side mirrors.Home Repair Tips : How to Fix a Blown Fuse
There are a few reasons why you might continually blow the same fuse. Be sure to check, first, that the fuse has the correct amperage rating for the circuit it is in.
Check what devices or lights are on that circuit, as it may be the case that a new amplifier pulls too much power, causing the fuse to blow. The more devices there are on one circuit, the heavier the amp load. Each electric device, including headlights and radios, pulls a certain amount of amps from the electrical system. The number embossed on the fuse, such as 5, 10 or 15, indicates how many amps may be pulled through the fuse before it blows.
Each wire in a car has a specific gauge or thickness. The amount and type of conductor used in a wire determines how much power it can handle before it overheats and melts. Electric devices also have these same limitations. They can only handle so much power before catastrophic failure and possibly a dangerous fire occur. Fuses protect both the wiring and the devices in the vehicle. A short circuit is simply a low resistance connection between the two conductors supplying electrical power to any circuit.
There are three main causes of a short circuit. Each one has tell-tale signs we look for during our investigation. The three causes from the most common to the least common are:. The location of the box and the assigned circuit for each fuse should appear in a diagram in the manual.
Most newer cars allow removal of the fuse box lid by hand or with a flat head screwdriver. Some fuses are designed to come out by hand, while others require a pair of tweezers or a smaller pair of needle-nose pliers.Just as most homes are equipped with fuses or circuit breakers, microwave ovens also have fuses that short out or blow in the event of an overload.
If your microwave oven blows a fuse, there are a couple possible causes. And if it blows the fuse for your kitchen, there also is a likely cause for that. Fuses are simple devices containing a wire made of a metal that melts at high temperature. When a short circuit occurs, the current through the fuse soars; the higher current means more heat, and the wire in the fuse melts, breaking the circuit. This process destroys the fuse, but it protects other more valuable components in the circuit that might otherwise be damaged by the high current.
Basically, then, a blown fuse in a microwave is the result of a surge in the current. This surge could result from several causes. Your microwave has what engineers call interlock switches that disable the oven when the door is open. Malfunctioning interlock switches or a badly misaligned door can cause the fuses to blow.
It's also possible the microwave's cooling fan may have failed, leading to overheating and melting the element in the fuse. Another possible problem is a short in the controller or near the line cord that feeds power into the microwave unit. If you have a short in the controller or near the line cord, the new fuse usually blows again immediately.
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The fuse also blows again if there is a short in the microwave magnetron or generator, the part of the microwave that actually produces the microwave radiation to cook the food. The location of the generator depends on the model you have; typically it's located behind a perforated screen overlooking the chamber that houses your food.
You can disconnect the generator by unplugging the wiring connecting it to the cavity thermal fuse and the other circuitry; the location of these elements depends on the model, so consult the manufacturer's instructions for details. The microwave will not heat food with the generator disconnected, but if you are able to select a cycle and initiate it as you normally would without blowing the fuse again, then the short may be within the generator itself.
Sometimes there is no short, and the fuse has gone bad without any particular cause. In this case, replacing the fuse solves the problem.
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If the fuse blows again, however, then it is likely you have a larger problem such as a short in the controller. And if using your microwave blows the fuse for the whole kitchen, the problem is usually fairly straightforward: You have too many appliances on the same circuit.
Disconnecting one or more of them should solve the problem. Based in San Diego, John Brennan has been writing about science and the environment since Hunker may earn compensation through affiliate links in this story.
Blown fuses in microwaves can result from several different problems. Share this article. John Brennan.Most homes built afteras well as older homes that have updated electrical services, have circuit breakers that control the electrical circuits in their homes.
But in older homes that haven't been updated, the electrical circuits are protected and controlled by fuses located in a central fuse box. These devices serve the same function as circuit breakers to protect against circuit overloads and short circuits, but rather than resetting them when they "trip," you must replace fuses when they burn out "blow".
Two different types of fuses control volt circuits and volt circuits in older electrical systems. For volt circuits, the fuses are small ceramic screw-in devices that fit into threaded sockets in the fuse panel, much the way lightbulbs screw into lamp sockets.
Inside the fuse, there is a metal ribbon through which all the current on the circuit passes. The ribbon is sized to match the circuit wire gauge, and if too much current passes through the ribbon, it melts through, or "blows," and the circuit goes dead. The face of the fuse has a small glass window through which you can see the metal ribbon, and when a fuse blows, you will see the metal ribbon melted through, or a cloudiness in the glass. Screw-in fuses are typically amp or amp fuses, or occasionally amp.
For volt circuits that control major appliance circuits, such as an air conditioner or electric range, the fuses are small cartridge devices that fit between metal contacts, usually fitted into a fuse block that can be pulled out from the fuse panel in order to change the fuses. Cartridge fuses are usually used for volt appliance circuits that draw 30, 40, or 50 amps. Like circuit breakers, fuses are sized to match the gauge of the circuit wires. This prevents the circuit wires from drawing more power than they can handle.
Using correct fuse sizes is, therefore, a crucial safety feature that can prevent fires due to circuit overloads. Tales are told of people who replaced burned-out fuses with a copper penny inserted into the fuse socket—a solution that did restore power to the circuit but also created an immediate danger of fire since there was no longer any limitation to how much power was drawn through the circuit wires.
A newer type of fuse called an Edison-base has a specially shaped base that prevents the wrong-sized fuse from being inserted into the socket. Once the bases are fitted into the fuse sockets, only fuses of the proper size can be fitted into them. If your fuse panel does not have Edison bases, it is a good idea to install them.
There are two conditions that can cause a fuse to blow. First, and most commonly, when too many lights or plug-in appliances draw power from the circuit, it can overload the capacity of the fuse and cause the metal ribbon inside the fuse to melt through. The result is that all lights, outlets, and appliances powered by the circuit will go dead suddenly.
When you examine the fuse, you will likely notice that the metal ribbon located behind the glass window is melted through, or you will notice a fog or cloudiness in the window, indicating a very sudden melting of the ribbon. The immediate solution here is to replace the fuse with one of the same size. Longer term, though, you will need to move some plug-in appliances into other circuits to avoid another overload and another blown fuse.
Appliances that heat such as toasters or clothes irons or those with motors such as vacuum cleaners are especially prone to causing overloads, since their power draw is fairly large, especially when they first startup. Another cause of a blown fuse occurs when a hot wire somewhere in the system touches either the grounding pathway or a neutral wire.
This is what is known as a short circuitand it typically occurs because of loose wire connections, damaged wires somewhere along the circuit, or an internal wiring problem in some appliance plugged into the circuit. A mis-wired lamp, for example, can cause a short circuit and blown fuse if it is plugged into an outlet.
Or wires that have been eaten through by rodents in walls can cause a hot wire to touch the grounding path or a neutral wire. The immediate symptom is the same as for an overload—the metal ribbon inside the fuse burns through and all lights and fixtures along the circuit go dead.
But in the case of a short circuit, merely replacing the fuse will likely cause the new one to blow immediately—unless the short circuit has been fixed. Diagnosing the location of a short circuit can take patience.You go to plug in something or reach to flip on a switch and. Your circuit breaker has tripped again. Sure, you can just reset the circuit breaker each time it trips.
If power has gone off in a certain area of your home rather than all over the house, the problem may be a tripped circuit breaker. If there are two breakers or fuses for one area, such as the kitchen, take care to detail which part of the kitchen each of the two switches controls. To help determine what caused the problem, unplug all the items on the circuit before resetting the breaker. Keep in mind that circuit breakers and fuses are actually safety devices for our protection when electrical malfunctions occur.
If you ever find yourself in a situation where you are experiencing issues with your electrical systems, take a moment to go over your options. This may be a good opportunity to review your electrical warranty coverage. When your home's electrical system malfunctions, you need expert assistance. Enjoy the reliability and security of an AHS Home Warranty, which can include coverage of major components of your home's electrical system.
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3 Reasons Your Circuit Breaker Keeps Tripping
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Get a Quote It only takes a few seconds.Are your lights or wipers not working? It could be because of a blown fuse in the fuse box. When this happens, you have no way of powering some electrical components.
If you often find that the fuse keeps blowing in the car more often, then you need to find the fault and fix it. Get to learn more about what would cause a fuse to blow. Before we get to understand why the fuse keeps on blowinglet's get to know more what a fuse is all about. A fuse is an important electrical component inserted in circuits, and you get blown to prevent damage to an expensive component. Whenever there is more current than the system would handle, then the fuse element would melt and thus disconnecting the current from flowing.
What this means that you do not get any power to the different electrical components in line with that blown fuse. Until when you get to find the fault and fix it, then more fuses would end up getting blown as a preventive measure. A number of things can lead to a fuse keeps blowing in a car and all have to be checked and repaired to avoid spending more on the fuses.
The common issue with fuses blowing would be because of faulty wiring. The faulty wiring or even the defective wiper motors would often lead to the excessive current flow in a system. What this does is result in a blown fuse each time a new one is installed. If the motors cannot be repaired, then you might have to replace them entirely. Having defective switches is another way of ending up with short circuits.
The short circuit is not a good thing for the fuse, which would find it as a fault thus blowing in the end. It is the same thing for a shorted motor; it would end up causing a shorted motor.
There are a number of ways this could go when it comes to dealing with a blown fuse. The important thing is to understand what is causing the fuse to keep blowing. The simple fix is often replacing the blown fuse and test the car again. If the fuse does not blow, it might be an easy fix because there was a power surge in the system.
For the case of where there has been a continuous blowing of the fuses, it is important that you do a thorough check for the wiring connection to find some of the loose connections and deal with them.